Serpentine Belts vs. Stretch-Fit Belts

Serpentine Belts vs. Stretch-Fit Belts

One of them doesn’t require a tensioner.

In the late 2000s, automakers added a new type of belt to take some of the load off the main accessory-belt drive. 

It’s called a stretch-fit belt, or stretch belt. GM, for example, started using stretch belts to power the air-conditioning compressor on some 2009 models with the LS V-8 engine. 

So, why stretch belts? Well, in addition to removing some of the load off the serpentine belt, stretch belts allow for better packaging and solve NVH problems that can occur with a longer serpentine belt. Less belt means less tension, and fewer noise and vibration problems.

Also, stretch belts have a unique internal construction that allows them to function without the need for idler arms and tensioners. Eliminating the need for a tensioner allows automotive engineers to reduce the number of components that share the primary belt drive, reduce belt-drive friction losses, save weight and design more compact accessory drives.

This video is sponsored by The Pronto Network.

You May Also Like

Measuring a Serpentine Belt

Use the correct tool to measure the effective belt length at the cord line.

How do you measure a serpentine belt with no part number on it?

Would you measure the inside with the ribs or the backing of the belt? Should it be measured on or off the pulleys? What would you use to measure the length of the pulley – a string, ruler or tape measure? Do you measure the outside or inside circumference of a multi-ribbed belt?

How Corrosion Can Ruin a Vehicle’s Brakes

Typically, the main culprit of friction-material separation is corrosion.

Selling Brake Pads for Electric Vehicles

Electric vehicles and hybrids have a built-in disadvantage regarding brake noise.

What Is Spark Plug Indexing?

Spark plug indexing is the orientation or placement of the ground electrode at a specified direction in the combustion chamber.

Recommending OE-Quality Ball Joints and Tie-Rod Ends

Today’s state-of-the-art high-performance tie rods and ball joints put original-equipment quality into the aftermarket’s hands.

Other Posts

Pronto Network’s Roos: ‘Another Defining Year’ for Aftermarket

Robert Roos is president of The Pronto Network.

Robert Roos
Unboxing a Mass Airflow Sensor

These are new units and not remanufactured.

United Motor Products’ Rick Maxwell Is an Industry ‘Lifer’

Rick and Bill talk about what it means to continue the legacy of a family business.

A Simple Strategy to Reduce Fraudulent Returns [VIDEO]

Members of the Automotive Sales Council talk about the “Check the Part” campaign.